0,25 giờ

Nhớ tick cho tớ nhé

15 phút = \(\frac{1}{60}\) giờ x 15 = \(\frac14\) giờ

Quãng đường trong 2 giờ đầu là :

15 × 2 = 30 ( km )

Quãng đường trong 1 giờ tiếp theo là :

12 × 1 = 12 ( km )

Người đó đã đi được số km là :

30 + 12 = 42 ( km )

Tick cho mình vs nha

Ta có: \(13,25:0,5+13,25:0,25+13,25:0,125+13,25\times96\)

\(=13,25\times2+13,25\times4+13,25\times8+13,25\times96\)

\(=13,25\times\left(2+4+8+96\right)\)

\(=13,25\times110=1457,5\)

\(\dfrac{2}{x}=\dfrac{5}{6}\)

=>\(x=2\times\dfrac{6}{5}=\dfrac{12}{5}\)

Giải:

\(\frac{2}{x}\) = \(\frac56\)

\(x\) = 2 : \(\frac56\)

\(x\) = 2 x \(\frac65\)

\(x\) = \(\frac{12}{5}\)

\(\left(\dfrac{5}{2}+\dfrac{7}{12}\right)\times12\)

\(=\dfrac{5}{2}\times12+\dfrac{7}{12}\times12\)

=30+7

=37

:

\(\dfrac{19}{15}\times\dfrac{23}{14}\times\dfrac{15}{19}=\dfrac{19}{19}\times\dfrac{15}{15}\times\dfrac{23}{14}=\dfrac{23}{14}\)

\(\dfrac{x-1}{2023}-\dfrac{1}{10}-\dfrac{1}{15}-\dfrac{1}{21}-...-\dfrac{1}{120}=\dfrac{5}{8}\)

=>\(\dfrac{x-1}{2023}-\left(\dfrac{1}{10}+\dfrac{1}{15}+...+\dfrac{1}{120}\right)=\dfrac{5}{8}\)

=>\(\dfrac{x-1}{2023}-2\left(\dfrac{1}{20}+\dfrac{1}{30}+...+\dfrac{1}{240}\right)=\dfrac{5}{8}\)

=>\(\dfrac{x-1}{2023}-2\left(\dfrac{1}{4}-\dfrac{1}{5}+\dfrac{1}{5}-\dfrac{1}{6}+...+\dfrac{1}{15}-\dfrac{1}{16}\right)=\dfrac{5}{8}\)

=>\(\dfrac{x-1}{2023}-2\left(\dfrac{1}{4}-\dfrac{1}{16}\right)=\dfrac{5}{8}\)

=>\(\dfrac{x-1}{2023}-2\cdot\dfrac{3}{16}=\dfrac{5}{8}\)

=>\(\dfrac{x-1}{2023}=\dfrac{5}{8}+\dfrac{3}{8}=\dfrac{8}{8}=1\)

=>x-1=2023

=>x=2024

\(x\) + \(\frac{35}{56}\) = \(\frac78\)

\(x\) = \(\frac78\) - \(\frac{35}{56}\)

\(x\) = \(\frac{49}{56}\) - \(\frac{35}{56}\)

\(x\) = \(\frac{14}{56}\)

\(x=\frac14\)

a: \(\dfrac{32\times50}{48\times25}=\dfrac{32}{48}\times\dfrac{50}{25}=\dfrac{2}{3}\times2=\dfrac{4}{3}\)

b: \(\dfrac{56\times27}{49\times36}=\dfrac{56}{49}\times\dfrac{27}{36}=\dfrac{8}{7}\times\dfrac{3}{4}=\dfrac{3\times2}{7}=\dfrac{6}{7}\)

c: \(\dfrac{121\times42}{77\times54}=\dfrac{121}{77}\times\dfrac{42}{54}=\dfrac{11}{7}\times\dfrac{7}{9}=\dfrac{11}{9}\)

a: \(56\times89-46\times89\)

\(=89\times\left(56-46\right)\)

\(=89\times10=890\)

b: 700+197-200+203

=500+(197+203)

=500+400

=900

a) 56 x 89 - 46 x 89

= (56 x 89 - 46 x 8)

= (56 - 46) x 89

= 10 x 89

= 890

b) 700 + 197 - 200 + 203

= (700 - 200) + (197 + 203)

= 500 + 400

= 900

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